1. Field of the Invention
The present invention relates to a mask for beam exposure such as charged particle exposure, particularly, electron beam exposure, and X-ray exposure, and a method for manufacturing the same.
2. Description of the Related Art
Generally, in the manufacture of semiconductor devices, a photolithography technology using ultraviolet rays has been indispensible for forming photoresist patterns. However, as the integration of semiconductor devices has been developed, a lithography technology using charged particle beam exposure, particularly, electron beam exposure and X-ray exposure has been developed, since the wavelength thereof is much smaller than that of ultraviolet rays. For example, in an electron beam lithography technology, a mask for electron beam exposure is used to form electron-beam resist patterns.
Prior art masks for electron beam exposure are of a stencil type. However, the stencil type masks hardly provide endless patterns. This will be explained later in detail.
Other prior art masks for electron beam exposure is of a membrane type. However, when terminated patterns are formed in the membrane type masks, openings for the terminated patterns cannot be completely perforated in the masks, so that the contrast of electron beams is deteriorated. Also, since the electron beams are scattered by the membrane structure, the blurring of the electron beams is increased. Thus, a higher resolution cannot be realized for the terminated patterns. This will be explained later in detail.
It is an object of the present invention to provide a mask for beam exposure such as electron beam exposure capable of realizing high resolution terminated patterns as well as surely realizing endless patterns.
Another object is to provide a method for manufacturing such a mask.
According to the present invention, in a mask for beam exposure, a membrane structure for endless patterns and a stencil structure for terminated patterns are provided in combination.